From this year's ETech (Emerging Technology) conference, this is an illuminating presentation which looks into our energy usage and how we might resolve our energy needs with the problem of climate change.

Saul Griffith (the speaker) has made a detailed investigation of his personal energy usage, and presents how he plans to reduce his energy footprint to match how he'd like to live his life. I think he does an excellent job of explaining some difficult to grasp numbers and weaves the varied energy and climate change threads into an understandable picture.